Rock drill



Oct. 23, 1934.

-M. c. HUFFMAN 1,977,636

ROCK DRILL Filed Feb. 21, 1931 2 sheets-sheet 1 "44. A mm.

0f.23,1934. MCQHUFFMAN 1,977,636

Roux DRILL Filed Feb. 2l. 1931 2 sheets-sheet 2 5f/1.@ mmm.

Patented ct. 23, 1934 A f v UNITED STATES' PATENT OFFICE ROCK DRILL Mervin Chester Huifman, Claremont, N. H., as-

Vsignor to Sullivan Machinery Company, a corporation of Massachusetts Application February 21, 1931, Serial No. 517,521

a 3 Claims.' (Cl. 121-47) This invention relates to rock drills, and more drill runner, is secured. Rotation of the piston 3 particularly to improved drill steel rotation mechis eiTected by means of a` ratchet controlled sysanism for rock drills ofthe hammer type tem of elements including a forwardly extending -Y An object of this inventionis to provide an imrifle bar 16 having spiral grooves 17 therein, which 5 proved rock drill rotation mechanism. A further cooperate with a rifle nut 18 threadedly mounted 6o object is to provide an improved drill `steel rotainthe rear end of the piston 3. At its rear end the tion, mechanism for a` rock drill of thehammer rifleV bar 16, which extends coaxally throughY the type having embodied therein improved release. valve and a closure member 19 for the valve means lfor such rotation fmechanism. Still anchest, is formed with a pawl carrying portion 21.

10 other object is to provide in a rock drill of 4the This portion carries a series of pawls 22resilient- 65 hammerpiston type improved drillfsteel rotation ly pressed toward ratchet engaging position by mechanismV ofthe intermittent ratchet and pawl plungers 23 and springs 24, and the pawls 22 are type operated bythe hammer piston of the drill adapted to engage a series of: ratchet teeth 25 and having embodied therein improved release formed within a ratchet ring men'iber 26. This means for the rotation mechanismwhereby, when member is rotatably supported within a chamber 70 desired, rotation of `the drill steel may be disforming member 2'7 positioned to the rear of the continued while the hammer piston continues to valve chest head member 19 and has a cylindrical operate; Still another object is to provide an periphery 28 guided within a cylindrical bore 29 improved pressure fluid governed friction control formed within the member 27. The ratchet ring 20 for a rock drill rotation mechanism. These and member 26 has a rearwardly projecting hollowv75 other objects and advantages `of this invention boss SO'Within whose interior a projection 31, upon will, however, hereinafter more fully appear. the rifle bar member, is rotatably supported, and

In the accompanying drawings, in which I have Whose exterior periphery is provided with a series, shown for purposes of illustration one embodiherein four, of longitudinal grooves 32. The boreV nient which the invention may assume in prac- 29 in the member 27 is of reduced diameter at its 50 tice,- innerportion 34, and permitting a slight longi- `Fig.V 1 is a side elevational view of afrock drill tudinal movement under certain conditions, is of the stoper type in which the illustrative emprovided with a number of longitudinally extendbodiment of the invention is incorporated. i l ing. internal `grooves 35 extending lengthwise of Fig. 2 is a longitudinat axial sectional view on this reduced bore. A series of friction brake discs 85 the line 2-v-2 of Fig. 1. 36 and 37,.having thereon ears designated re- Fig. 3 is a' section taken through the axis of the spectively 33 land 39, are assembled within the re'- rotation handle, socalled. duced bore 34, surrounding the boss 30, the discs Fig. 4 is a transverse section on the plane of the 36` engaging, through their ears and the grooves line4-4 of Fig. 2.H e l 35, the member 27; and the grooves 32 andears 90 Fig. 5 is atransverse section on the plane ofthe 39 holding the discs 37 in non-rotative relation line '5-.5 of Fig. 2, through the ratchet mechato the boss 30. A follower or brake loading memnism l V- ber 40 is placedat the end'of the reduced bore Referring te the drawings, Figl 1 Shows a, rock 34 remote from the motor. The member 26 is 40 drilling motor generally designated 1 and comslightly shorter than the distance between the 95 prising a cylinder 2 Within which a. hammer pisclosure member 19 and the shoulder at the rearton 3 is mounted for reciprocation. This hammer Ward end of the full-sized bore29, and the member piston isV provided With a striking` barv 4 having 40 has a Slightly greater DOteIltal movement. splineways 5 therein by which rotation is adapt- Provision iS made whereby pressure may be e13- v ed to be imparted through any suitable chuck plied tothe follower member 40 to effect fric- 100 mechanism housed within a chuck housing 6, to tional engagement 0f thel brake diSCS, and lel arock drill steel 7. The iluid supply to the drillsultant holding stationary at will of the `ratchet ingmotor is from an air line 8 andv under the member 26. For this purposea cylindrical bore 41 control of a throttle valve mechanism 9, and uid is arranged to the rear of the longitudinally exdistribution to the motor is effected'through a tending grooves 35, and a packing member or cup 105 sleeve valve 10 mounted Within a valve chest 11 washer 42 is arranged Within this member and formed in amember 12mounted at the rear end of in engagement with the follower 40. A passage the cylinder; The member 12 supports the throt- 43, to which fluid is supplied through a port 44 in tle valve mechanism grand valso has a boss 13 the throttle valve, serves to admit fluid to apply within vwhich the handle member l14, Vheld by the pressure to the. brake discs, and relieving of the `11p pressure upon these discs is made possible by a vent passage 46 and a vent valve 47 arranged within the handle 14, the valve 47 being reciprocable in a bore in the handle and normally held by a spring 49 in a position to prevent communication b-etween a port 5l in` the plunger and a port 52 opening to atmosphere.y By restricting the fluid supply as at 43a control is much facilitated, and free reciprocation without rotation for spotting is possible. The usual cleansing fluid supply tube 54 is mounted in a gland member `55 at the rear end of the member 27 and a feed vcylinder 55 is held in assembled relation with the several parts of the drilling motor by a collar 57 and side rods 58 whose forward ends carry nuts 59 which cooperate with lock washers 60. Y

From the foregoing description solfar given, the mode of operation of this mechanism will bel clearly apparent. It will be evident that thepiston 3 will not rotate if the ratchet ring 26 is free to rotate, but that upon holding of the ratchet ringstationary, rotation will be imparted to the` piston 3 and thus tothe hollow drill steel 7. Upon appropriate adjustment of the mechanism 9 air admitted from the pipe or connection 8 to the passage 43 through the port 44 will act upon therear surface of the cup "washer Li2-and press the brake follower 4G forwardly, thereby effecting a frictional engagement of the discs 36 and 37 and -locking the ratchet ring relative Atothe drill asia whole. vDuring rotation of the drillsteel, it will beappreciated that thevalve plunger 47is in the position shown in Fig 3,'and

that airadmittedI through the passage`43 isl prevented from escaping. YBy moving the` plunger 47 inwardly the passage lmay be caused to communicate with the passage 52 to` varying degrees,

and by properly proportioning the size of the passages and regulating the degree of communication between ports 51 and 52, a variable degree of lockingof the ratchet can rbe effected, the ratchet beingpractically'freed from free rotation, or variably retardedfromY rotation as desired by a suitable manipulation of the plunger 47.- During spotting no rotation, or very slow rotation isV desirable,and by the present mechanism any desiredcondition can be attained. The play of members 26 and 40 permits complete loosening of the friction discs, and on release of theair during heavy rotation,v the rearward motion'ofk the piston Vunder full aircpressure'will instantly relieve thefriction`V .i I:

-A'plurality ofl frictiondiscs arel provided and when thediscs are interleaved in alternate rela- ,tion as shown in Fig.: 2, the maximumgpossible frictional resistance isimparted tothe ratchet ring. However, vto suit varying conditions, .the

interleaved relation of the discs `may -be changed so that maximum frictional resistance of a smaller degree may be imparted to the' ratchet ring; for

instance, when a minimum resistance is desired,

all thediscs 36 are placedtogetheran'dheld stationary4 with the casing while the discs 35 are all placed together and secured to the ratchet ring; so that the frictional'effect is that of but two discs and the frictional resistance will be comparatively slight. By varying the interleaving different braking effects can be secured and the desired resultsobtained. It will be evident that when the rotation parts become overloaded the friction is'.`

so designedI as to slip, thereby preventing possible-breakage of the parts.

From the foregoing description it will be observed that I have provided a very .simple and vconvenient apparatus for controlling); the rotation throttle valvek of a drilling motor', and that a readily varied rate of rotation, or rotation at maximum speed, or no rotation at all, may be effected at will. It will be noted, moreover, that the mechanism is entirely free from any cam devices or the like requiring adjustment and complicated construction, and that by the mere manipulation of a conveniently disposed valve plunger, the desired control may be effected. These and other advantages of the invention will be clearly appar- .ent to those skilled in the art.

While there is in this application specifically described one form which the invention may assume in practice, itwill be understood that this for-m ofthe same isshown for purposes of illustration and that-the invention may be modified and embodied in various other forms without `departing vfromV its spirit or the scope of the appended claims.

What I claim as new and desire to secure by Letters Patent. is:

1..In a: rock drillingmechanism, thecombination witha drill steel actuating motor including a. hammer piston, of drill steel rotation mechanismoperated iby saidhammer piston including ani oscillatory pawl carrier, a rotatable ratchet ring having Lteeth' with Whichvthe pawlsfof said carrier are .engageable, said ratchet ring rhav-.- ing a rearward cylindrical portionhaving formed therein bearing means and said pawl carrier having a rearward bearingportion journaled in said bearing means, and Va Africtional `braking device for yieldingly holding said ratchetring against rotation including friction discs connected to the portion ofthe ratchet-ring surrounding said bearl kan oscillatory pawl carrier, farotat'able ratchet ring having teethv with which thepawls of said carrier areengageable, saidratchet ring having aV rearward cylindrical portionr having formed therein bearing 'means and said-pawlcarrier having arearward bearing 'portionf journaled in said bearing means, andl a frictional braking device for yieldingly holding said ratchet ring against' rotation including frictiondiscs-connected to the porton ofthe ratchet ring 'surrounding said bearing means Vand therearward bearing portion ofy ther'pawl carrier, friction dises connected toal relatively stationary element of the drill and; interleaved. .withsaidt friction discs, and means operable at will for forcing said discs together ill-ff;

into frictional engagement to hold. yieldingly said ratchet ring againstv rotation thereby to effect drill steel `rotation or'to permit slippage orreleaseof. said discs. to vary the rotation ofthe ratchet ring "or to. release entirelysaid ratchetnl ring for free'rotation and vincluding-Y a disc-like plunger arranged at the` rear of'said Ybearing portion of the ratchetpring,v and engaging thev rearmost of said discs,.said stationarypart ofthe drill; havinga guide bore for Asaid. plunger.

3. In a rock drilling mechanism, the combination with a drill steel actuating motor including a hammer piston, of drill steel rotation mechanism operated by said hammer piston including an oscillatory pawl carrier, a rotatable ratchet ring having teeth with which the pawls of said carrier are engageable, said ratchet ring having a rearward cylindrical portion having formed therein bearing means and said pawl carrier having a rearward bearing portion journaled in said bearing means, and a frictional braking device for yieldingly holding said ratchet ring against rotation including friction discs connected to the portion of the ratchet ring surrounding said bearing means and the rearward bearing portion of the pawl carrier, friction discs connected to a relatively stationary element of the drill and interleaved with said friction discs, and means operable at will for forcing said discs together into frictional engagement to hold yieldingly said ratchet ring against rotation thereby to effect drill steel rotation or to permit slippage or release of said discs to vary the rotation of the ratchet ring or to release entirely said ratchet ring for free rotation and including a disc-like plunger arranged at the rear of said bearing portion of the ratchet ring and engaging the rearmost of said discs, said stationary part of the drill having a guide bore for said plunger, and uid means for actuating said plunger including an alined bore formed in the stationary part ofthe drill, a packing member engaging the walls of said latter bore and said plunger for actuating the latter and means for supplying fluid to said latter bore to act on said packing member. l

NIERVIN CHESTER HUFFMAN. 

